As is known in the art, there has been a recent trend to develop media access control (MAC) protocols for wavelength division multiplexed (WDM) local area networks (LANs). Most of these LANs are based on a broadcast star, and require global time synchronization (or a global common clock) to coordinate access to timeslots for data transmission to and from the nodes (sometimes referred to as optical terminals). Most of the protocols also use an out-of-band Aloha-based collision scheme to access the control channel, or a reservation system that uses a slotting scheme for data transmission and a minislot scheme for access to the reservation and control channel. One notable exception is Modiano's scheme, which uses an unslotted system for data transmission, but still uses a contention based system to access the control channel.
As the packet switching marketplace has matured, despite the trend of over-provisioning of bandwidth, there has been growing interest in providing greater levels of quality-of-service for high performance computer processing networks to ensure application performance, user prioritization, and compliance with service level agreements. For switched-ethernet networks, which is a currently predominant networking technology used in data/transaction processing centers, approaches to provide quality of service (QoS) include such schemes as priority queuing and weighted fair queuing, as well as numerous congestion control mechanisms. Some have been implemented into commercial systems, while others are in the standardization process or in academic literature.